RANCHO MIRAGE — The state Attorney General’s Office approved the merger of the Betty Ford Center in Rancho Mirage and Minnesota-based addiction treatment provider Hazelden, it was announced today.

The approval makes the merger official, making the now-Hazelden Betty Ford Foundation the country’s largest nonprofit treatment group, according to foundation officials. The boards of both organizations approved the merger in September.

The Betty Ford Center in Rancho Mirage will keep its name, with the added tag, “a part of the Hazelden Betty Ford Foundation.” The names of the other treatment centers will stay the same, except for the Women’s Recovery Center on Hazelden’s Center City, Minn., campus, which will be renamed in Ford’s honor, according to foundation officials.

“Mother would be pleased. Her pioneering achievements of ensuring access to quality treatment will be expanded through the new Hazelden Betty Ford Foundation,” said Susan Ford Bales, daughter of the former first lady who co-founded the addiction treatment center that bears her name. “I am especially pleased, as I know Mother and Dad would be that her legacy of commitment to patients and their families will continue for generations to come through the work of a wonderful Betty Ford Center staff that has now been united with the outstanding leadership and staff of the Hazelden organization.”

The Hazelden Betty Ford Foundation has 15 sites in nine states, with residential and outpatient services based on a 12-step, abstinence-based treatment model. The organization also has an addiction and recovery publishing house, a graduate school of addiction studies, a prevention training program, an addiction research center, an education arm for medical professionals and a children’s program.

“We are now well-positioned to respond to the challenges and opportunities presented by health care reform and the rapidly changing marketplace,” said new foundation President and CEO Mark Mishek. “Together, we will be able to better utilize the addiction treatment field’s most extensive expertise, knowledge and data to accelerate innovation in treating the chronic disease of addiction and expand our already robust national system of care.”

Ford and Hazelden announced in June that they were pursuing an alliance.

The Betty Ford Center was founded in Rancho Mirage in 1982 by the former first lady and has served 100,000 people, according to its website. Hazelden was founded in 1949 and has facilities in Minnesota, Oregon, Illinois, New York and Florida.